x264 aspect ratio question

[BabaG]

been trying to use x264 encoder to generate .264 files readable by adobe encore for some simple bluray authoring and am making enough progress to be thinking about the next problem: aspect ratio.

i have material that is 4x3 1440x1080p with square pixels. i read someplace that the bluray spec only accepts 1920x1080. if that is true, what is the best way for me to conform this 4x3 material? can it be done directly in the x264 encoding process? what i want for projection is a pillarboxed image.

thanks,
BabaG

[Sharc]

I think you have to add left and right borders of 240 pixels width each, and encode at 1920x1080. Then you are safe.

Blu-ray accepts 1440x1080p but only for 16:9 DAR (Display Aspect Ratio). You may want to try 1440x1080 and encoded explicitely with --sar 1:1. It may work on some players, but I am afraid it's not blu-ray standard compliant.

[BabaG]

thanks, Sharc.

can i add those borders directly in the x264 transcode? if so, what's the command for that?

thanks again,
BabaG

[Sharc]

I doubt that one can add borders with x264 built-in filter options. I always use avisynth for this purpose, like:
AddBorders(240,0,240,0).

Btw., out of curiosity I tried 1440x1080p 4:3 source with --sar 1:1 on various playback devices:
- MPC-HC => ok
- VLC => ok
- WDT TV => ok
- SONY standalone Blu-Ray Player + TV: => NOT ok. It always stretched the picture to DAR 16:9. I could not even manually force it to 4:3.

[BabaG]

thanks again, Sharc. much appreciated.

i think i need to start another thread on this. i have more info that gets farther afield than the aspect ratio subject.

BabaG